Any idea for day trip? (Seoul)

Hi everyone, my name is Jeena, originally from Korea as well but has been working and living outside of the country more than 10 years.

I am visiting home during lunar new year but since I haven't had a chance to explore my country, so want to plan a day trip on coming Thursday(11th). I was thinking Jeju or Jeonjoo, but have no specific idea yet. This is embarrassing even though I am a Korean but do not know here very well! Hehe

So I thought it could be an idea to ask for suggestions on good day trip locations in winter! And furthermore, if anyone is also planning a day trip on Thursday, may I join you? Haha don't worry I am a fun and outgoing and also not a scary person, I am also not seeking a date here. Just looking for good chance make a fun memory in this holiday.

Then looking forward to hearing from anyone!

Best regards,

Jeena